Airplane wing flap and slat mounting



' J. H. BENNETT ETAL.

AIRPLANE WING FLAP AND SLAT MOUNTING Feb. 20, 1951 Filed Aug. 16, 1947 2Sheets-Sheet 1 JAMES H. BENNETT JAMES A. WEBB Wu. J

l 1951 r J. H BENNETT ETAL- 2,542,792

AIRPLANE WING FLAP AND SLAT MOUNTING Filed Aug. 16, 1947 2 Sheets-Sheet2 JAMES H, BENNETT JAMES A. WEBB Patented Feb. 20, 1951 AIRPLANE WINGFLAP AND SLAT MOUNTING James H. Bennett, Baltimore, and James A. Webb,Essex, Md., assignors to The Glenn L. Martin Company, Middle River, Md.,a corporation of Maryland Application August 16, 1947, Serial N 0.769,002

Claims. 1 v

This invention relates to a novel flap, slat and shutter assemblysecured to the trailing edge of a wing, more particularly to themounting and actuating mechanism arranged to affordadequate mechanicaland aerodynamic functions with greatest simplification of parts.

The flap is an auxiliary airfoil on the trailing edge of the wing thatcan be lowered to an attitude of high lift or a position of high drag.Flips heretofore used have been more or less effective, limited by themechanism required to position the flap downwardly and rearwardly of thewing; T0 properly position a flap, it is necesary to get an effectivepivot point well below the lower surface of the wing. Many types ofmechanism have been worked out to get the effective pivot point belowthe wing without having the mechanism extend below the wing. None ofthem is the equivalent of the flap arrangement of this invent on whereinthe pivot point is actually located below the wing on a bracket where itwill be most effective, and the bracket faired to decrease aerodynamicresistance. The purpose of a slat is to increase the maximum liftcoeflicient by controlling the air flow over the flap when it is in thedown position. Slats have been mounted in several ways so that they willbe positioned in the space between thetrailing edge of the wing and theflap, and usually the mounting is a duplicate of the mounting of theflap, and requires some sort of actuating mechanism to position it onits mounting in space relative to the flap. A shutter has been usedbetween the lower surface of the wing and the leading edge of the flapto close the space and render the lower surface of the wing smooth andcontinuous when the flap is in the inoperative position. Such shuttershave required an intermittent motion mechanism operated by the movementof the flap, because it must operate quickly during in tial movement ofthe flap and stay open until almost final movement of the flap.

The mounting mechanism and the actuating mechanism of flap, slat andshutter arrange ments has always involved a great weight pen alty. "Itis an object of this invention to provide a very eiiective high liftdevice for an airplane wing with a minimum of weight.

It is a further object of this invention to pro-V portion of the flapforming a quadrilateral linkage arrangement whereby the slat is properlypositioned with respect to the flap and moves in response to themovement of the flap.

It is a further object of this invention to provide a flap mounting withan actual pivot point well below the wing for proper position of theflap with respect to the wing.

It is a further object of this invention to provide a slat mountingemploying structure common to the mounting of the flap that serves notonly as a slat mounting, but also actuates the slat in response tomovement of the flap.

It is a further object of this invention to provide a quick opening andquick closing shutter mechanism actuated by and in response to themotion of the flap.

Further and other objects will become apparent from the description ofthe accompanying drawings which form a part of this disclosure and inwhich like numerals refer to like parts.

In the drawings:

Figure 1 is a sectional view through the airplane wing showing themounting of the flap and slat in the inoperative position.

Figure 2 is a view of the fiap and slat in the high lift position.

Figure 3 is an exploded perspective view showing the essential parts ofthe slat, flap and mounting.

and actuating mechanism.

The flap l shown in Figure 1 is mounted along the trailing edge of wing2 by several hinge assemblies, which good practice dictates will be atleast three. Figure 1 is a typical section through such a flap mountinghinge bracket. Members 3 and 4 are secured to member 5 which is securedto the structure of the wing so that members 3, 4 and 5 forma'bracketsupporting an upper pivot point 6, intermediate the upper and lowersurfaces of the wing profile, and a lower pivot point 1 below the lowersurface of the wing profile. Slat 8 has a bracket 9 supporting a pivotpoint that is located forwardly and downwardly from the slat in theoperative position and pivotally secured to member 3 at pivot point 6.,JSlat 8 has a bracket I0 supporting a pivotal connection H for member23 adjacent the trailing edge on the lower side of the profile of the.

slat. Flapvl has a main hinge bracket l2 sup porting a pivot pointforwardly and downwardly from the leading edge of the flap in theoperative position, and is pivotally connected to member 4 at pivotpoint I.

Bracket 13 is secured intermediate bracket [2 Figure 4 is a fragmentaryview of the shutter a? and pivotally supports the lower end of member23. Bracket I5 is mounted on bracket 12 and pivotally supports one endof push rod (6 which moves crank 24 to move shutter I! about pivot pointl8 as will be explained in detail later. Shutter ll servesto close thegap-betweenthe. trailing edge of the Wing and the leading edge of theflap on the lower side of the wing profile when the flap assembly is inthe up or inoperative pQesition. Shutter I! moves to the position shownin Figure 2 when the flap is operating in the high lift or high dragposition.

A faired cover for the hinge bracket iszproivided by members It and 2G.1\ iember:l9,,is se-. cured to the lower surface of the trailing edge ofthe wing and provides a faired, streamlined cover around the bracket todecrease drag due to the 4 be made without departing from the spirit andscope of the appended claims.

We claim as our invention:

1. An airplane wing flap mounting comprising a plurality of bracketmeans rigidly affixed on the trailingedge of an airplane wing extendingdownwardly and to the rear thereof, each of said bracket meanssupporting an upper and lower piyot, said upper pivot being locatedwithin the bracket mechanism extending below the. wing Cover portion issecured to the lower surface of the flap, and moves therewith astheiiapmoves.

and 2 is shownin-perspective view 3"as the endhinge. Intermediate hingesfor the flap and slat are shown in Figure 3. Bracket 2| aremounted onthe underside of the fiap and pivot points 22 are aligned with pivotpoint 5 and similarly mountedfor a similar function. Figure 3 shows pushrods 58 connected to each of the bracket assemblies l2 to operate thecorresponding section of the shutter I! between the hinge assemblies;Bracket 25 is secured to the leading edge of the fiap and affords apivotal sup-port for push rod-25. Push rod 25 is operated to move theflap from the up or inoperative position to positions of high lift orhigh drag.

Brackets 2'; are secured to the underside of flap l and afford mountingflanges for securing fairing 28 in place around the hinge bracket.

Push red It consists of a sleeve 28telescoping with rod 29. Push rod Itcan be adjusted by nut 30 so that red 29 will bottom in sleeve 28, for apredetermined minimum length. When one endof push rod 16 is secured tobracket l5. and the. other end to crank 2 because of itsminimum length,it will exert a force on crank:2:4*; secured to shutter I7, that willhold the shutter in the plane of the under surface of the wing. Link 311 i pivotally secured to shutter H at 32. other end of link 3! issecured to the wing structure at 33 with a. tension spring 34; When the:flap i's-moved away from the up position, telescoping push rod itpermits shutter IT to be moved upwardly by spring 3 3 into the position"shown in Fig. 3. As the flap is movedt'o a high;

lift position, or further to a high drag position; telescopic member 28merel rides on telescopic member 2! When the flap is raised, push'rod I6does not-move crank EQ-to-return shutter I 1 to the=closed positionuntil the flap is almost in the up position, 'at'which time portion 29bottomsin portion 28 of push rod E6 to move" crank 24' and shutter IT tothe closed position with the final motion of the flap. Thus, it will beseen that with motion of push rod 2'5 to move the flap, all otherrequired motions for properly positioningthe slat and opening theshutter are effected with this flap mounting. The support and actuationof the parts of the wing for high lif't andhigh' drag are achieved in asimple and light weight construction to secure the advantages of thehighest practical wing loading. v

It is to be understood that certain changes,

alterations, modifications and substitutionsycan' The wing profile andsaid lower pivot being located below the under side of the wing, a flapbracket meansextending forwardly and downwardly secured; to said lowerpivot, aslat having bracket means secured thereto extending forwardlyand downwardly fromthe leading edge thereof supported on said upperpivot, linkage means pivoted at a point on said slat adjacent thetrailing edgelthereof, and a point on said flap adjacent the noseportion thereofl'to control the incidence of, said slat as the flap ismoved to a vpositionof high lift or drag, a two-part streamline housing.faired around the'portions of said bracketsex tending below the lowersurface of said wing, one,

a portion of said housing securedto said wing structure and the otherportion of said. housing se-j cured to said flap. g

2. An airplane wing flap mounting comprising, a. plurality of, bracketmeans rigidly affixedfon'r the trailing edge of an airplane wingextending,- downwardly and to the rear thereof, each of said bracketmeans. supporting an upper and, lower pivot, said upper pivot beinglocatedwithinr the wing profile and said lower pivot being located.below the under side of the wing, a flap bracket; means extendingforwardly and downwardly secured to said lower pivot, a slat havingbracket" means secured thereto extending forwardly and; downwardly fromthe leading edge thereof supported on said upper pivot, linkage meanspiv-.

oted at a point on said slat adjacent the trailing edge thereof, and apoint on said flap adjacent. the nose portion thereof to control theincidence of said slat as the flap is moved to a position of; high liftor drag, a two-part streamline housing faired around the portions ofsaid brackets, extending below the lower surface ofsaid wing, oneportionof said housing secured to said wing. structure and. the otherportion of said housing; secured to said flap, a shutter memberpivotally j mounted on said wing so constructed and are. ranged that itcan be moved to one positionto close the opening between the lowersurfaceoffthe flap and the lower surface of the wing between. saidbracket housings and to another positionre tracted within the wing whenthe slat and flap are moved to a high lift position, spring actuated,means to move said shutter to said position with in the wing, ,a pushrod having one end secured. to said flap bracket, the other end of. saidpush; rod'adapted to permit said shutter to be moved;

to the position within the wing when the fljapi islowered and to movesaid shutter to the first. mentioned position when said flap is raised.

3. An airplane wing flap. mounting,compris-. ing a plurality of bracketmeans rigidly afiixed'. on the trailing edge of an airplane wingextend'- ing downwardly and to the rear thereof, eacliof. said bracketmeans supporting an upper. and. lower pivot, said upper pivot beinglocated within the. wing profile and said lower pivot being. locatedbelow the under side of. the Wing, afiap. bracket means extendingforwardly and down-- wardly secured to said lower pivot, a slat hav--'ing bracket means secured thereto extending for wardly and downwardlyfrom the. leading, edge;

5 thereof supported on said upper pivot, linkage means pivoted at apoint on said slat adjacent the trailing edge thereof, and a point onsaid flap adjacent the nose portion thereof to control the incidence ofsaid slat as the flap is moved to a position of high lift or drag, atwo-part streamline housing faired around the portions of said bracketsextending below the lower surface of said wing, one portion of saidhousing secured to said wing structure and the other portion of saidhousing secured to said flap, a shutter member pivotally mounted on saidwing so constructed and arranged that it can be moved to one position toclose the opening between the lower surface of the flap and the lowersurface of the wing between said bracket housings and to anotherposition retracted within the wing when the slat and fiap are moved to ahigh lift position, means actuated in response to the initial movementof said flap to fully retract said shutter within the wing and othermeans cooperating with said shutter actuating means to extend theshutter to close the opening between the wing and flap when said flap israised substantially in the inoperative position.

4. An airplane wing flap mounting comprising a plurality of bracketmeans rigidly affixed on the trailing edge of an airplane wing extendingdownwardly and to the rear thereof, each of said bracket meanssupporting an upper and lower pivot, said upper pivot being locatedwithin the wing profile and said lower pivot being located below theunder side of the wing, a flap bracket means extending forwardly anddownwardly secured to said lower pivot, a slat having bracket meanssecured thereto extending forwardly and downwardly from the leading edgethereof supported on said upper pivot, linkage means pivoted at a pointon said slat adjacent the trailing edge thereof, and a point on saidflap adjacent the nose portion thereof to control the incidence of saidslat as the flap is moved to a position of high lift or drag, a two-partstreamline housing faired around the portions of said brackets extendingbelow the lower surface of said wing, one portion of said housingsecured to said wing structure and the other portion of said housingsecured to said flap, a shutter member pivotally mounted on said wing soconstructed and arranged that it can be moved to one posithe otherportion thereof secured to said crank arm adapted to permit said shutterto be moved to the position within the wing upon initial movement of theflap, and to move said shutter to the first mentioned position uponfinal movement of the flap to the inoperative position.

5. An airplane wing flap mounting comprising a plurality of bracketmeans rigidly arfixed on the trailing edge of an airplane wing extendingdownwardly and to the rear thereof, each of said bracket meanssupporting an upper and lower pivot, said upper pivot being locatedwithin the wing profile and said lower pivot being located below theunder side of the wing, a flap bracket means extending forwardly anddownwardly secured to said lower pivot, a slat having bracket meanssecured thereto extending forwardly and downwardly from the leading edgethereof supported on said upper pivot, linkage means pivoted at a pointon said slat adjacent the trailing edge thereof, and a point on saidflap adjacent the nose portion thereof to control the incidence of saidslat as the flap is moved to a position of high lift or drag, a two-partstreamline housing faired around the portions of said brackets extendingbelow the lower surface of said wing, one portion of said housingsecured to said wing structure and the other portion of said housingsecured to said flap, a shutter member pivotally mounted on said wing soconstructed and arranged that it can be moved to one position to closethe opening between the lower surface of the flap and the lower surfaceof the wing between said bracket housings and to another positionretracted within the wing when the flap is moved to a high liftposition, and a push rod extending from said wing within said fairedhousing and being pivotally secured to said fiap bracket meansintermediate said lower pivot and said flap structure to move saidshutter as said flap is moved.

JAMES H. BENNETT. JAMES A. WEBB.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Num er Name Date 2,289,704 Grant July 14, 19422,334,975 Williams Nov. 23, 1943 FOREIGN PATENTS Number Country Date728,528 France Apr. 12, 1932 OTHER REFERENCES Aviation, of November1945, pp. 150 and 151.

